An alpha channel gives you degrees of transparency. If you don't have clips with areas that are semi-transparent or totall transparent, you don't need it.

And you don't really need ProRes 4444, either: the image quality is no better than ProRes 422, but the file sizes are MUCH larger. If you're going to re-render your clips at least 6 generations deep, HQ or 4444 would be appropriate. Otherwise, you're just eating up storage space.

The alpha channel would be for something created in a graphics program intended to be superimposed over other video. The alpha channel cuts out the background. (This is a very simple explanation...you can do more complex stuff, but it doesn't seem relevant here). Sounds like you are not doing that, so you don't need it.

For your case, Pro Res 4444 would actually be of benefit. Dave assumed you were like many people who post, who shot something with a DSLR camera (or something much worse), which is already highly compressed and would not magically improve in quality just by converting it to Pro Res 4444...only bloat the file size.